Social structure and seasonal variation in the behaviour of Eulemur mongoz

Data presented here were collected during a 10-month study carried out on the mongoose lemur, Eulemur mongoz, at Anjamena in northwestern Madagascar. Baseline information is provided on behaviour and assessed for seasonal variation. Given the highly seasonal nature of the environment, remarkably little behavioural variation was observed. This may be directly linked to the cathemeral activity pattern, where differential movement into either the diurnal or the nocturnal 'niche' could reduce the effect of selective seasonal pressures, thus reducing behavioural and ecological adaptation to seasonal variation. The behavioural mechanisms of reinforcement of the pair bond through close proximity, mutual anogenital marking, paternal participation in the care of offspring and territoriality are all in accord with the general characteristics of monogamy in primates. The feature of mate monopolization by males, proposed as typical of monogamous social systems, seems to be more attributable to females in E. mongoz, as only they exhibit high levels of intrasexual aggression. Female dominance, characteristic of most species of lemur, may thus include more than just female feeding priority in E. mongoz.